MACROMEDIA FLASH 8-EXTENDING FLASH Manual page 270

Returns
A Boolean value of
true
Description
Method; writes the specified string to the specified file (as UTF-8). If the specified file does
not exist, it is created. However, the folder in which you are placing the file must exist before
you use this method. To create folders, use
Example
The following example attempts to write the string "xxx" to the file mydata.txt and displays
an alert message if the write succeeded. It then attempts to append the string "aaa" to the file
and displays a second alert message if the write succeeded. After executing this script, the file
mydata.txt will contain only the text "xxxaaa".
var URI = "file:///c|/temp/mydata.txt";
if (FLfile.write(URI, "xxx")) {
alert("Wrote xxx to " + URI);
}
if (FLfile.write(URI, "aaa", "append")) {
alert("Appended aaa to " + fileURI);
}
See also
FLfile.createFolder()
270 Objects
if successful; otherwise.
false
FLfile.createFolder()
,
FLfile.exists()
.